Locomotive valve gear



Nov. 11, 1930.

v. R. STEWART LOCOMOTIVE VALVE GEAR s Sheets-Sheet 1 Fi led Nov. 50, 1926 Nov. 11, 1930. v. R. STEWART LOCOMOTIVE VALVE GEAR 3 Sheets-Sheet 2 Fil'd Nov Nov. 11, 1930.

V. R. STEWART LOCOMOTIVE VALVE GEAR Filed Nov. 30, 1926 3 Sheets-Sheet 5 dotted lines,

Tatented Nov. 11, 1930 PATENT orries VICTOR R. STEWART, OF GLENSIDE, PENNSYLVANIA LOCOMOTIVE VALVE GEAR Application filed November 30, 1926. Serial No. 151,732.

This invention relates ments in valve gears for to certain improvethrec-cyhnder locomotives, one object being to operate the valve of the middle cylinder by means 01: a valve gear which obtains its motion from the middle cross-head 111 combin ation with a crank on the outside of one of the driving wheels.

A further object of align the three links wh the invention is to 1ch control the valve mechanism, two of said-links being on one side of the locomotive and the other link on the opposite side thereof, and a smgle reversing The invention also relates to other shaft for shifting the rods actuated by the said links.

details which will be fully described hereinafter.

In the accompanying Fig. 1 1s a side new frame in dotted lines and drawings showing the engine the valve mechanism on both sides of the locomotive in full lines;

Fig.

a portion of the valve the locomotive only;

Fig. 3 is a plan view showing the frame 2 is a view similar to Fig. 1, showing gear on one side of and wheels in dotted lines;

I? a is a sectional v 5 is a sectional v g and v is an enlarged lines ifor the links.

The frame 2, which are mounted iew on the line 1-1,

iew on the line 5-5,

sectional view 011 the KAN,

(3-6, Fig. 1, illustrating the bearings 1 of the locomotive is shown by as well as the driving-wheels on axles 3, 3 and mounted in suitable boxes in the frame 1.

The axle 3 is a crank-axle,

having a crankpin i, to which is coupled the connecting rod of the central cylinder 5. The connecting rods of the outer cylinders 6 and 7 are coupled indicated at 8, Figs.

the driving-wheels middle cylinder is the middle cylinder is operated without interfering with the valve side cylinders. combined movement 3 head 8. The crank 9 i gear of the two out- This is accomplished by the of the crank 9 and crosss a double crank on one of the wheels having pins 5)" and 9". A rod 2%: connects the pin 9 on this crank 9 to a reversing link 10 which is located close to the reversing-link 11. Directly-back of the valve chest 01 the central cylinder in the present instance is a transverse rock-shaft 12. A red 18 connects the link lO to an arm 2?) on' the rock-shaft 12. The rock-shaft 12 is I mounted inbe'arings in a rocker 14. The trunnions of this rocker are mounted in a bracket 16 secured to, the frame or forming a part of the cylinder structure Mounted on the rock-shaft is ahead to which'is' attached the valve-rod 25 ofthe valve ofthe central cylinder 5. On the rock shaft 12 is an arm 22 which is connected by a link 21 to thecross-head. I r V "The rock-shaft 12, being supported on the rocker M, permits the free moven ient' of the said shaft 12 on a line'para-llel to the center line of the locomotive,"and as this shaft is connected to the valve-stem ofthe middle cylinder, it moves the valve in accordance with the movement of the middle cross-head 8 which is'connected to the rock-shaft 12. The movement of the shaft12 the inner arm opensthe valve at the end of the piston stroke,and the'movement by the outer arm 23 gives thefvalve its full travel and maxiium port opening.

The two reverse links 10 and 11 are arranged as show'n'in Figs. 3 and 5, so as to take up'as little space'as'possible.

There are three hearings on a bracket26. The inner trunnion 11 of the link 11 extends into a cavity in the trunnion 10 0f the link 10 which forms its bearing. The trunnion 10 of the link 1Q is mounted in the central bearing 27 ot'the bracket 26.

The other trunnion of the link 10 is mounted in an outer bearing 28 and the outer trunnion of the link 11 is mounted in an outer bearing 29 (see Fig. 6).

The links thus placed in alignment allow the rods 17, 18 and 19 to be raisedand low ered by a' single reversing shaft 20- extending across-the locomotive as shown in Fig. 3. The shaft has three arms 31 which are connected by links 32 to the ends of their respective rods 17, 18 and 19.

I claim 1. The combination in a valve gear for a three-cylinder locomotive, of two side cyl inders and a central cylinder; a valve chest for each of said cylinders; valves in the chests; a transverse reversing shaft; three reversing links, two of said links being on one side of the locomotive and one on the opposite side thereof; three levers in substantial alignment, said levers being connected to the valves; rods connecting the levers with their respective links, said rods being connected to the reversing shaft; a single axle; two cranks on one end of said axle connected to the two links on that side of the locomotive; and a single crank on the oppositerend of said axle connected to the single link on that side of the locomotive.

2. The combination in a valve motion for I a three-cylinder locomotive, of three valves;

a transverse reversingshaft extending from one side of the locomotive to the other; two links on one side of the locomotive; a single linkonthe opposite side thereof, the three links being in alignment; means driven from one of the axles of the locomotive for actuating each of said links; means controlled by the links for independently actuating the valves, said means being connected to the transverse reversing shaft; and connections between said means and the transverse reversing shaft. g

3. The combination in-a valve mechanism for a locomotive, of a reversing shaft; two reverse links on one side of the locomotive, said links being arranged side-by-side and each link having trunnions at each side, the inner trunnion of one side being ofgreater diameter than the inner trunnion of the adjoining link, said enlarged trunnion having a cavity therein, the inner trunnion of the other link extending into said cavity in the enlargedtrunnion; a fixed bearing on the locomotive extending between the two 7 links and in which the enlarged trunnion is mounted; fixed bearings for the outside trunnions of the two. links; means for actuating the links; and rods extending through the links; and means connecting the rods with the reversing shaft.

4. The combination in a valve mechanism for .a three-cylinder locomotive, of three valves; a rod attached to each valve; three reversing links, two of said links being arranged close together on one sideof the locomotive; a single link on the opposite side thereof, said links being in transverse alignment; an axle having wheels; a'doublecrank' on one end of said axle; pinson the double crank, said pins being'connected to thetwo reversing links on that-side ofsthejlocomotive and the crank at the opposite end-of the axle; connections betweenthe said crank V and the single link on that side of the locomotive; rods connecting the links with the valve rods of their respective cylinders; a transverse reversing shaft having three arms; connections between the arms and their respective rods; three cross-heads; and levers connecting said rods with their re spective cross-heads.

' 5. The combination in a valve mechanism for a locomotive, of a frame; a fixed bracket thereon; a rocker mounted in the bracket; a transverse shaft carried by the outer end of said rocker, said shafth-aving two arms; a piston cross-head; connections between the said cross-head and one of said arms of the rock-shaft'; reversing 'mechanism; connections between the other arm and said reversing mechanism; and a valve rod having a head mounted on the rock-shaft. 

